Our estimates show a pandemic with an Rt that remains around teh value of 1, following a sustained period of increasing infections since Sep 6th, the start of the autumn school term. This prolonged rise in the number of infections, initially in school-age children, is now only apparent among the >25yrs. The pandemic data that we use typically inform incidence up until about two weeks ago. At this time in allregions the probability that Rt is greater than 1 is in excess of 50% and greater than 75% in seven regions. At the current high levels of incidence we estimate a drop in Rt of almost 0.2 over the following two weeks, bringing the Rt values close to 1.0.
The data on deaths within 60 days of a positive test show a recent peak having been gradually increasing since mid-June. The decline that followed now appears to have arrested with a suggestion that they are increasing once again as anticipated last week. Our model predicts this increase will continue for a further two weeks before an estimated peak around November 8th. This peak is at 171 deaths per day which is low in comparison to the peaks of the first two waves of infection.
Plots of the IFR over time show that from the end of January we estimate a decreasing IFR in all adult age groups, but most steeply in the older ages. This drop indicates the benefits of immunisation against death over and above the benefits against infection. Following this drop, there has been a period of plateau followed by a slight increase to 3.2% (3.0%–3.4%) in the over-75s and 0.21% (0.20%–0.22%) overall.
For context, in addition to the data used here, the numbers of reported new positive tests (by date of specimen) had been steadily increasing since the second week of September. These case numbers are, however, beginning to show initial evidence of decline, though they are highly dependent on the volume and targeting of testing, the public’s testing behaviour and significant reporting delays, and therefore are difficult to interpret. Hospitalisations show similar behaviour with a plateau in admissions, since 18th October,The prevalence of infection, as estimated by the ONS Coronavirus Infections Survey, has instead risen consistently over the last five weeks to 1.8% in England, the highest level it has been since the second week of January, 2021.
Real-time tracking of an epidemic, as data accumulate over time, is an essential component of a public health response to a new outbreak. A team of statistical modellers at the MRC Biostatistics Unit (BSU), University of Cambridge, are working to provide regular now-casts and forecasts of COVID-19 infections and deaths. This information feeds directly to the SAGE sub-group, Scientific Pandemic Influenza sub-group on Modelling (SPI-M), and to regional Public Health England (PHE) teams.
We fit a transmission model (Birrell et al. 2020) to a number of data sources (see ‘Data Sources’), to reconstruct the number of new COVID-19 infections over time in different age groups and NHS regions, estimate a measure of ongoing transmission and predict the number of new COVID-19 deaths.
We use:
Data are stratified into eight age groups: <1, 1-4, 5-14, 15-24, 25-44, 45-64, 65-74, 75+, and the NHS England regions (North East and Yorkshire, North West, Midlands, East of England, London, South East, South West).
Value of \(R_t\), the average number of secondary infections due to a typical infection today.
The percentage of a given group that has been infected.
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 0.00 | -0.01 | 0.00 |
| East of England | 0.00 | -0.01 | 0.01 |
| East Midlands | -0.01 | -0.03 | 0.00 |
| London | 0.01 | -0.01 | 0.02 |
| North East | -0.02 | -0.04 | 0.00 |
| North West | 0.00 | -0.02 | 0.01 |
| South East | 0.01 | -0.01 | 0.02 |
| South West | 0.00 | -0.02 | 0.01 |
| West Midlands | -0.01 | -0.03 | 0.00 |
| Yorkshire and The Humber | -0.02 | -0.03 | 0.00 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 432.01 | 105.04 | NA |
| East of England | NA | 63.66 | NA |
| East Midlands | 46.21 | 24.34 | 531.65 |
| London | NA | 73.50 | NA |
| North East | 38.54 | 18.77 | 243.09 |
| North West | 158.42 | 32.09 | NA |
| South East | NA | 136.09 | NA |
| South West | 176.27 | 38.86 | NA |
| West Midlands | 55.53 | 24.94 | NA |
| Yorkshire and The Humber | 43.14 | 21.25 | 260.92 |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | 181.67 | NA |
| East of England | 443.82 | 48.00 | NA |
| East Midlands | NA | NA | NA |
| London | 112.79 | 35.78 | NA |
| North East | NA | NA | NA |
| North West | NA | 63.74 | NA |
| South East | 67.27 | 27.93 | NA |
| South West | NA | 72.53 | NA |
| West Midlands | NA | 815.16 | NA |
| Yorkshire and The Humber | NA | NA | NA |
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 0.02 | 0.01 | 0.02 |
| East of England | 0.03 | 0.01 | 0.04 |
| East Midlands | 0.01 | -0.01 | 0.02 |
| London | 0.02 | 0.00 | 0.03 |
| North East | 0.00 | -0.01 | 0.02 |
| North West | 0.01 | 0.00 | 0.03 |
| South East | 0.02 | 0.01 | 0.04 |
| South West | 0.02 | 0.01 | 0.03 |
| West Midlands | 0.01 | 0.00 | 0.03 |
| Yorkshire and The Humber | 0.01 | -0.01 | 0.02 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | NA | NA |
| East of England | NA | NA | NA |
| East Midlands | NA | 138.10 | NA |
| London | NA | NA | NA |
| North East | NA | 68.57 | NA |
| North West | NA | 721.60 | NA |
| South East | NA | NA | NA |
| South West | NA | NA | NA |
| West Midlands | NA | 1041.09 | NA |
| Yorkshire and The Humber | NA | 109.79 | NA |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 43.11 | 32.49 | 61.11 |
| East of England | 24.52 | 16.00 | 48.11 |
| East Midlands | 79.09 | 29.17 | NA |
| London | 37.79 | 21.13 | 174.54 |
| North East | 167.11 | 33.83 | NA |
| North West | 53.46 | 24.45 | NA |
| South East | 34.30 | 19.52 | 98.93 |
| South West | 34.70 | 20.05 | 110.10 |
| West Midlands | 58.35 | 27.14 | NA |
| Yorkshire and The Humber | 102.19 | 33.62 | NA |
## The execution of the prevalence code block will proceed if
## prev.dat exists and this is TRUE
## it is not and external report and this is FALSEThe shaded areas show periods of national lockdown, the green lines the dates (once confirmed) of the steps in the roadmap in the UK Governement’s COVID-19 Response – Spring 2021, and the red line shows the date these results were produced (22 Oct).
The figure below shows the probability that \(R_t\) is greater than 1 (ie: the number of infections is growing) in each region over time. Clicking the regions in the legend allows lines to be added or removed from the figure.
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